Field of the Invention
The invention relates to the field of bookbinding machines and machines for the gathering of books and volumes. In particular, it relates to an improved automatic machine for the continuous binding of books and brochures or booklets.
Automatic machines for the binding of groups of sheets are widely known. Those machines include one or more pneumatic clamps in which the sheets to be bound are inserted and which transport the group of sheets along an entire binding sequence. They also include a vibrating plane that aligns and a miller which trims the group of sheets to be bound, glue rollers and blades that spread the glue on the sheets, a casing-in device that positions each cover on the folding machine and a cover-pressing mechanism which presses the cover on to the group of sheets.
The bookbinding machines which are constructed as described above present a series of characteristics that slow down production and/or require the performance of manual operations.
The pneumatic clamp that transports the group of sheets is opened and closed mechanically and/or pneumatically by mechanisms of the machine, depending on the position of the sheets along their route. In the case of jamming of the mechanisms, or if the sheets must be removed for any other reason, it is necessary to force the opening of the clamp manually as well as to move the entire chain that transports the clamp forward or backward, with the risk of being injured and/or of making pieces of sheets or covers fall into the mechanisms of the machine.
The sheet levelling tables are positioned on various cams, in such a way as to permit their vertical adjustment depending on the edge that must be successively trimmed by the miller or millers. That system with cams for the adjustment of the levelling table does not ensure a correct horizontal adjustment of the table itself, and consequently as a result the sheets tend to be inclined with respect to the millers as well as to the cover that is successively applied.
The glue rollers and blades are partially immersed in a glue tank. Since different types of glue are used, it must be possible to remove the tank, the rollers and the blades either to change or to clean them. At present the tank, rollers and blades are positioned on a trolley in order to constitute a single unit. Therefore, a trolley is provided with rollers and blades for any type of glue, which represents a considerable encumbrance and a considerable weight to be handled.
It is accordingly an object of the invention to provide an improved automatic machine for the continuous binding of books and brochures, which overcomes the above-mentioned disadvantages of the heretofore-known machines of this general type.
With the foregoing and other objects in view there is provided, in accordance with the invention, an automatic machine for the continuous binding of books and booklets, comprising a sheet leveling device, trimming millers, an innovative glue spreading unit having rollers and blades, a chain, a series of innovative pneumatic clamps mounted on the chain for transporting groups of sheets to be bound along various stations, mechanisms controlling opening and closing of the clamps in various sections of a binding process, and a cover-pressing mechanism. Each of the clamps has a manual opening mechanism independent of the mechanisms controlling the opening and closing of the clamps.
The pneumatic clamps are adjustable and can hold the groups of sheets independently of their volume, up to a given maximum thickness. These pneumatic clamps are mounted on a chain that is generally ring-shaped and runs along the stations of the bookbinding process until the clamps return to a starting area where the groups of sheets are loaded.
The pneumatic clamps serve the function of transporting each group of sheets along the various processing stations and of preventing the individual sheets from moving relative to one another.
These pneumatic clamps include two vertical walls between which the groups of sheets are positioned. The opening and closing of the two parts of the clamp takes place through the use of mechanisms that are present partly on the clamp and partly on the fixed structure of the machine. The clamp is automatically opened, closed, or held in one of these two positions, depending on which section of the chain is being covered.
A second mechanism provided with an elastic element and an operating lever is applied to the clamp opening and closing mechanism. The second mechanism allows the two parts of the clamp to be opened at any given moment. The elastic element provides for keeping the two parts in the position controlled by the clamp opening and closing mechanisms of the new machine, while the lever counteracts the action of the elastic element and opens the two parts of the clamp as much as necessary to permit the release of the group of sheets held between them.
The second clamp opening mechanism allows an operator to remove the sheets that may be positioned incorrectly or jammed in the clamp.
In accordance with another feature of the invention, the sheet levelling device includes two horizontal plates disposed parallel to each other. The lower of the plates is permanently fixed to the machine, while the upper one supports a horizontal levelling table provided with vibrators.
The two horizontal parallel plates are joined through the use of connecting elements. One of these connecting elements is provided with a protrusion positioned beside the lower plate and provided with a round hole. An eccentric screw hinged to the lower horizontal plate is inserted in the hole. The rotation of the eccentric screw causes rotation of the corresponding connection element and consequently lifting or lowering of the upper horizontal plate. Since the two plates are joined by the connecting elements, the lifting or lowering of one of them causes the corresponding lifting or lowering of the others, and consequently the upper horizontal plate is lifted or lowered while remaining parallel to itself.
As a consequence of the above, the horizontal levelling table is also lifted and lowered while remaining parallel to itself, always in a horizontal position.
In this way, the sheets levelled by the levelling device mentioned above are always positioned correctly for the successive millers that will operate according to the thickness to be cut.
In accordance with a concomitant feature of the invention, the glue spreading unit includes two complementary parts, one of which is applied to the structure of the machine, while the other is interchangeable.
The part of the glue spreading unit applied to the structure of the machine includes a table or support hinged to the structure, in such a way as to rotate from an operating position beside the new bookbinding machine to a maintenance position in which the table or support is facing away from the bookbinding machine.
A mechanical coupling for the transmission of motion is provided on the structure of the bookbinding machine and on the rotary table or support. When the rotary table or support is placed in the operating position beside the structure of the machine, the mechanical coupling for the transmission of motion provides for transmitting motion to the components of the glue spreading unit. Other connections without the transmission of motion provide for centering the table or support in the correct position on the bookbinding machine.
The interchangeable part of the glue spreading unit substantially includes a tank provided with glue rollers and blades. The rollers partially protrude from an upper edge of the tank, since they take the glue present inside the tank with their lower side and spread it on the sheets with their upper side. The blades provide for adjusting the quantity of glue that the rollers deposit on the sheets.
The second interchangeable part is connected to the first rotary part through the use of either hooks or joints that ensure its correct position and of mechanical couplings which transmit motion from the bookbinding machine to the rollers.
Through rotation of the glue spreading unit it is possible to comfortably remove or service the assembly of the tank, the rollers and the blades and it is also possible to replace the assembly of the tank, the rollers and the blades specifically used for one type of glue with a different assembly specifically used for another type of glue and if necessary provided with heating elements.
Even the simple cleaning of the tank, rollers and blades is much easier, since they are light and not cumbersome.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an improved automatic machine for the continuous binding of books and brochures, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.